rgb与hsi模型转换matlab程序

数字图像处理:RGB与HSI模型转换Matlab程序 im1=imread( Fig6.30(01).jpg ); im3=im1; im1=im2double(im1); [m,n,q]=size(im1); % 获取图像的 RGB 3个通道 R=im1(:,:,1); G=im1(:,:,2); B=im1(:,:,3); % 改变通道来观察图像 figure,subplot(1,3,1),imshow(cat(3,R*0.5,G,B)),title( R通道减半 ); set(gcf, outerposition ,get(0, screensize )); set(gcf, NumberTitle , off , Name , 改变通道来观察图像 ); subplot(1,3,2),imshow(cat(3,R,G*2,B)),title( G通道翻倍 ); subplot(1,3,3),imshow(cat(3,R,G,zeros(m,n))),title( B通道为0 ); % 观察HSI通道图像 % 因系统没有rgb2hsi函数,只有rgb2hsv函数,所以自己编写程序实现 H=zeros(m,n); S=H; for i1=1:mfor i2=1:nnumerator=0.5*(R(i1,i2)-G(i1,i2)+R(i1,i2)-B(i1,i2));denominator=sqrt((R(i1,i2)-G(i1,i2))^2+(R(i1,i2)- B(i1,i2))*(G(i1,i2)-B(i1,i2)));theta=acos(numerator/denominator)*180/pi;if(B(i1,i2)<=G(i1,i2))H(i1,i2)=theta;elseH(i1,i2)=360-theta;endmin1=min(R(i1,i2),G(i1,i2));min1=min(B(i1,i2),min1);S(i1,i2)=1-3/(R(i1,i2)+G(i1,i2)+B(i1,i2))*min1;end end I=(R+G+B)/3; figure,subplot(1,3,1),imshow(H,[]),title( 色度图H ); set(gcf, outerposition ,get(0, screensize )); set(gcf, NumberTitle , off , Name , HSI通道图像 );subplot(1,3,2),imshow(S),title( 饱和度图S ); subplot(1,3,3),imshow(I),title( 强度图I ); % 从HSI转换回RGB模型并观察图像,系统也不自带hsi2rgb,仅自带hsv2rgb im2=zeros(m,n,3); for i1=1:mfor i2=1:nvalue1=I(i1,i2)*(1+S(i1,i2)*cos(H(i1,i2))/cos(pi/3- H(i1,i2)/180*pi));value2=I(i1,i2)*(1-S(i1,i2));switch (floor(H(i1,i2)/120))case 0im2(i1,i2,1)=value1;im2(i1,i2,2)=3*I(i1,i2)-R(i1,i2)-B(i1,i2);im2(i1,i2,3)=value2;case 1H(i1,i2)=H(i1,i2)-120;im2(i1,i2,1)=value2;im2(i1,i2,2)=value1;im2(i1,i2,3)=3*I(i1,i2)-R(i1,i2)-G(i1,i2);case 2H(i1,i2)=H(i1,i2)-240;im2(i1,i2,1)=3*I(i1,i2)-G(i1,i2)-B(i1,i2);im2(i1,i2,2)=value2;im2(i1,i2,3)=value1;endend end % 模型转换完毕,显示图像 figure,subplot(1,2,1),imshow(im1),title( 原图 ); set(gcf, outerposition ,get(0, screensize )); set(gcf, NumberTitle , off , Name , 原图与HSI转RGB通道图像对比 ); subplot(1,2,2),imshow(im2),title( HSI转RGB通道图像 ); % 给图像添加噪声 im3=imnoise(im3, salt R=im3(:,:,1); G=im3(:,:,2); B=im3(:,:,3); R=medfilt2(R);G=medfilt2(G); B=medfilt2(B); im4=cat(3,R,G,B); figure,subplot(1,3,1),imshow(im1),title( 原图 ); set(gcf, outerposition ,get(0, screensize )); set(gcf, NumberTitle , off , Name , 图像对比 ); subplot(1,3,2),imshow(im3),title( 加入椒盐噪声后图像 ); subplot(1,3,3),imshow(im4),title( 中值滤波后图像 );